Trackmania Nations Forever launching problem

hey guys,

im having a preoblem starting trackmania nations forever

i go to my steam library and start the game
launch trackmania nations forever
and then something is loading (maybe you know the win7 loading circle) but after 6 seconds the loading circle disappears and the game doesnt starts properly

i CAN find the game in my task manager but i cant see any Trackmania window opened on my desktop

also: if i launch the game and nothing happens the steam community says, that im in game


i have win7 64bit, a ATI geforce hd 5850 and 4GB RAM
this should deal with it...
but the mysterious thing is that i was able to start the game and play it on the same computer and same OS aboout 6 weeks ago...
can someone help me?


sorry for my bad english (8grade germany ;D )

PLEASE HELP!!!

[Nitekillr]

Go to your browser and type "tmtp://" (without the quotes, of course).